Aggregate coating apparatus



Dec. 6, 1938. K. E. M CONNAUGHAY AGGREGATE COATING APPARATUS Filed Sept. 2, 1936 f" -1 iii-" Patented Dec. 6, 1938 UNITED STATES PATENT OFFICE v 2,139,027 AGGREGATE COATING APPARATUS,v Kenneth E. McConnaughay, Otterbein, Ind. Application September 2, 1936, Serial No. 99,653

4ClaimS.

It is the object of my invention to produce a machine for coating aggregate with bitumen to produce a composition suitable for paving. More specifically, it is my object to produce a machine 5 in which the thickness of the bitumen coating applied to the aggregate particles may be varied as desired and in which aggregate particles of various sizes may be satisfactorily coated. A further object of my invention is toproduce a machine 10 of this type which will be simple in construction and economical to manufacture.

In carrying out my invention, I feed the aggregate from a bin at a regulated rate into a mixerconveyor, preferably a pug-mill mixer or screwl3 conveyor. As the aggregate passes through the mixer-conveyor, the bitumen is applied to it from a series of spray nozzles located along the path the aggregate travels and individually adjustable to regulate the quantity of bitumen applied. Con- 20 veniently, the mixer-conveyor is arranged in two sections. one extending generally horizontally beneath an aggregate hopper or bin and the second positioned to receive aggregate discharged from the first and inclined upwardly to elevate the fin- 25 ished product into a storage bin or other container. To prevent an accumulation of liquefied bitumen, which might interfere with the desired regulation of the thickness of the bitumen coating, I provide means for removing any excess 30 bitumen from the bottom of the second section of the mixer-conveyor, such bitumen being returned to the supply tank.

The accompanying drawing illustrates my invention: Fig. 1 is a side elevation of a portable 35 machine on which is mounted aggregate-coating apparatus in accordance with my invention, parts of the device being broken away to illustrate the construction more clearly; and Fig. 2 is a front elevation of the machine shown in Fig. l.

40 As illustrated in the drawing, the machine is arranged to be portable, and to this end the various elements of the aggregate-coating apparatus are supported upon a tractor III. Although the apparatus will be described as mounted on a 5 tractor, it is to be understood that in its broader aspects my invention is not limited to a portable machine.

Across the front end of the tractor l shown in the drawing I provide an aggregate hopper l I 50 beneath which is the trough l2 of a mixer-conveyor such as a pug-mill. The bottom of the hopper II is formed by a forwardly and downwardly inclined partition l3, the front edge, of

which is spaced from the front wall of the hopper as to provide an opening through which aggregate from the frame 11.

may feed into the trough l2. Desirably, there is associated with this opening some form of adjustable gate M by means of which the rate of aggregate-feed may be regulated.

The aggregate-coating apparatus includes an engine l6 which supplies the power necessary to drive the moving parts of the mechanism. As shown, the engine I6 is mounted in a transverse position on a frame H which is supported from the tractor l0. Driven from the engine I6 I provide a main shaft l6 and a counter-shaft l8 which extends transversely of the machine in front of the engine l0 and which, at its outer end, carries a sprocket I9 connected by a chain to a sprocket 2| on the end of the shaft 22that ex- 1.1 tends through the trough i2. Within the trough l2, the shaft 22 is provided with helically inclined blades 23 which operate, in the rotation of the shaft, to move the aggregate from left to right in Fig. 2. ,A jaw-clutch 25, operated by a suit- 20 able operating lever 26, controls the operative connection of the sprocket (9 to the shaft l8.

The material delivered from the right-hand end of the trough I2 is received in the lower end of a trough 30 which slopes upwardly and rear- 25 wardly to an elevated point of discharge. Within the trough 36 I provide mixing conveying means which are shown as in the form of helically inclined blades 3| mounted on a rotatable shaft 32 extending through the length of the trough 30.

For the purpose of driving the shaft 32 its upper end may be connected through mitre gears 35 with a transversely extending shaft 36 carrying a sprocket 31 which is connected through a chain 38 with the shaft I6. A jaw-clutch 40, operated 35 by a hand lever 4|, may be employed to control the operative connection between the sprocket 31 and the shaft 36.

To supply bitumen to the aggregate moving through the troughs l2 and 36, I provide spray 40 pipes and 46 which extend longitudinally of such troughs near the tops thereof. Each of the pipes 45 and 46 is provided with a series of longitudinally spaced discharge nozzles 41 through which the bitumen is discharged. I prefer to make the nozzles individually adjustable to regulate the quantity of bitumen discharged from each.

contained in a tank 48, conveniently supported The pipes 45 and 46 are con-. nected together and to the discharge pipe 49 of a pump 50 the inlet side of which is connected through a pipe 5| with the tank 46. The pump T The bitumen supply for the pipes 45 and 46 is 50 v 50 may conveniently be driven through a chainand-sprocket drive from the shaft l5.

To prevent the accumulation liquid bitumen in the lower end of the trough 30,

drawn into the pipe 55, and also to prevent any aggregate from falling into bitumen that may be in the lower end of the trough 30, I-provide a screen 60 which extends across the lower end of the trough above the opening in the pipe 55.

The mixing and coating apparatus as so far described can be employed asa stationary unit to produce a bituminous paving composition, the

discharge opening can be regulated by an adjustable gate 61. Since the material emerging from the upper end of the trough 30 will be discharged into one end of the hopper 65, I prefer to employ means for preventing such material from overflowing the hopper before the hopper is completely full. As indicated in the drawing, this means may take the form of a screw-conveyor 68 which extends longitudinally of the hopper 65 near the .top thereof. The conveyor 68 may be driven through a chain 59 from a sprocket l0 loosely mounted on the counter-shaft l8 and adapted to be operatively connected thereto by a jaw-clutch 1| under the control of a suitable hand lever 12.

In the operation of the machine, the bin H is filled with aggregate and the tank 48 with bitumen in liquid form, preferably an emulsified bitumen. When the machine is in operation, ag-

shaft 22 rotates, the aggregate is moved along the trough l2 and discharged into the lower end of the inclined trough 30. During its passage through the trough l2, the aggregate receives bitumen sprayed from the nozzles 41. Any bituthe quantity which will screen 60, to the tank 48 by the pump 55.

The aggregate discharged into the trough 30 from the trough I2 is elevated in the former by the action of the helical blades 3| on the shaft 32 and, at the upper is discharged through the determined by the position is distributed on the road As the machine moves along the road,

By proper regulation character of the coating applied to the aggregate pipe 45 are used at all, near the lower end thereof.

I claim as my invention:

1. Aggregate coating apparatus, comprising a ing near its bottom, and means for distributing along said hopper aggregate discharged from said second trough.

ENNETH E. MCCONNAUGHAY.

they are only the nozzles 

